Barcelona midfielder Arturo Vidal says the players know Tuesday's clash with Athletic Bilbao is a must-win.

Vidal and Barcelona will desperately need three points when they face Athletic Club on Tuesday evening.

"It will be a very intense and very hard game and we have to improve because Athletic are very complicated," he explained.

"We have to recover as soon as possible between matchdays."

The Chilean also addressed the new format of the Champions League which will take place in August.

"If we beat Napoli, it'll be one-legged games and I like that because you're playing for it all in 90 minutes," he said.

"In those circumstances is when important players have to show up, I want to do that."